<!DOCTYPE HTML>
<html><head>
<!-- Any copyright is dedicated to the Public Domain.
     http://creativecommons.org/publicdomain/zero/1.0/ -->
<style>
body { width: 450px }
input { font-size: 12px }
</style>
<!--
In a 450px container, the minimum font size at 15em per line is 30px.
This means we map 0px-45px into 30px-45px, so 12px gets mapped to 34px.
-->
</head>
<body><input type="checkbox">I have a bike</body>
</html>